原标题：ADI ADA4433-1全差分SD视频滤波放大器方案

　　ADI公司的ADA4433-1是全差分SD视频滤波放大器,5阶低通视频滤波器, 具有输出电池短路保护9STB)和对地短路保护(STG)以及极好的视频特性和低功耗,输出过压保护高达18V.0.1 B平坦度到3MHz,-3 dB带宽10MHz,27MHz的抑制为45dB,主要用在汽车后视照相机,汽车视频电控单元(ECU),视频监视系统.本文介绍了ADA4432-1主要特性,方框图,应用配置电路图,和ADV7391/ADV7393视频编码器的应用电路图,DC耦合电路图以及ADA4433-1评估板主要特性,电路图和材料清单.

　　ADA4433-1: Fully Differential SD Video Filter Amplifier with Output Short-to-Battery Protection

　　The ADA4432-1 (single-ended output) and ADA4433-1 (differential output) are fully integrated video reconstruction filters that combine overvoltage protection (short-to-battery [STB] protection) and short-to-ground (STG) protection on the outputs, with excellent video specifications and low power consumption. The combination of STB protection and robust ESD tolerance allows the ADA4432-1 and the ADA4433-1 to provide superior protection in the hostile automotive environment.

　　The ADA4432-1 is a single-ended input/single-ended output video filter capable of driving long back-terminated cables.

　　The ADA4433-1 is a fully differential video filter that can be used as a fully differential input to a differential output or as a single-ended input to a differential output, allowing it to easily connect to both differential and single-ended sources. It is capable of driving twisted pair or coaxial cable with minimal line attenuation. Differential signal processing reduces the effects of ground noise, which can plague ground referenced systems. The ADA4433-1 is ideal for differential signal processing (gain and filtering) throughout the signal chain, simplifying the conversion between single-ended and differential components.

　　The short-to-battery protection integrated into the ADA4432-1 and ADA4433-1 protects against both dc and transient overvoltage events, caused by an accidental short to a battery voltage up to 18 V. The Analog Devices, Inc., short-to-battery protection eliminates the need for large output coupling capacitors and other complicated circuits used to protect standard video amplifiers, saving space and cost.

　　The ADA4432-1 and ADA4433-1 feature a high-order filter with −3 dB cutoff frequency response at 10 MHz and 45 dB of rejection at 27 MHz. The ADA4432-1 and ADA4433-1 feature an internally fixed gain of 2 V/V. This makes the ADA4432-1 and ADA4433-1 ideal for SD video applications, including NTSC and PAL.

　　The ADA4432-1 and ADA4433-1 operate on single supplies as low as 2.6 V and as high as 3.6 V while providing the dynamic range required by the most demanding video systems.

　　The ADA4432-1 and ADA4433-1 are offered in an 8-lead, 3 mm × 3 mm LFCSP package. The ADA4432-1 is also available in a 6-lead SOT-23 package. All are rated for operation over the wide automotive temperature range of −0℃ to +125℃.

　　ADA4432-1主要特性:

　　Qualified for automotive applications

　　Output overvoltage (short-to-battery) protection up to 18 V

　　Short-to-battery output flag for wire diagnostics

　　Output short-to-ground protection

　　Fifth-order, low-pass video filter

　　0.1 dB flatness to 3 MHz

　　−3 dB bandwidth of 10 MHz

　　45 dB rejection at 27 MHz

　　Ultralow power-down current: 13.5 μA typical

　　Low quiescent current

　　7.6 mA typical (ADA4432-1)

　　13.2 mA typical (ADA4433-1)

　　Low supply voltage: 2.6 V to 3.6 V

　　Small packaging

　　8-lead, 3 mm × 3 mm LFCSP

　　6-lead SOT-23 (ADA4432-1 only)

　　Wide operating temperature range: −0℃ to +125℃

　　ADA4432-1应用:

　　Automotive rearview cameras

　　Automotive video electronic control units (ECUs)

　　Surveillance video systems

　　图1.ADA4432-1方框图

　　图2.ADA4432-1应用案例配置电路图

　　图3.ADA4432-1和ADV7391/ADV7393视频编码器应用电路图

　　图4.ADA4432-1视频滤波器和ADA4830-1差分放大器的DC耦合电路图

　　ADA4433-1评估板

　　Evaluation Board for the ADA4433-1, Fully Differential Video Filter Amplifier Offered in 8-Lead LFCSP Evaluation Board for the ADA4433-1, Fully Differential Video Filter Amplifier Offered in 8-Lead LFCSP

　　ADA4433-1评估板主要特性:

　　Fully assembled and tested

　　Enables quick customer evaluation

　　Edge-mounted SMA connector provisions

　　Easy connection to test equipment and other circuits

　　图5.ADA4433-1评估板外形图

　　图6.ADA4433-1BCP-EBZ评估板电路图

　　ADA4433-1BCP-EBZ评估板材料清单: